Abstract I am requesting funding for a 5-year renewal of K24 AA022586, ?Training and Research Program on Alcohol use by Persons with or At-Risk for HIV?. Over this initial K24 funding period, my research program has flourished, progressing from observational studies of alcohol's impact on HIV risk and outcomes to alcohol intervention studies via new U01 and R01 funding. These studies leverage alcohol biomarkers (phosphatidylethanol ? PEth and ethyl glucuronide ? EtG) and biosensors that regularly monitor alcohol in sweat (transdermal alcohol) as objective outcome measures and as intervention tools (for incentive-based interventions). My mentees have also achieved success during this period in publishing (41 mentee first- authored publications) and grant funding (8 awards for K01, R36, R34, R01, and U01 proposals). I propose to renew this K24 funding to build upon this research and mentoring success in two new ways. (1) I propose to expand my alcohol/HIV research mentoring by including training in the use of alcohol biomarkers and biosensors. This includes mentoring scholars to study alcohol measurement via biomarkers or biosensors (e.g. exploring combinations of biomarkers with biosensors, examining biosensor and point-of-care biomarker use in the real world, etc.). It also includes mentoring investigators conducting research in HIV comorbidities (e.g. tuberculosis, viral hepatitis, polysubstance use) and in vulnerable populations (i.e. adolescents, infants of HIV- infected women, those experiencing intimate partner violence) to incorporate the role of alcohol use into their research, using biomarkers or biosensors. To facilitate these expansions to my mentoring, I will use K24 renewal funds for biomarkers and biosensors for mentee-led pilot projects. (2) I propose to take deliberate steps to increase mentoring of persons who identify as under-represented minorities (URM) thereby expanding the workforce of HIV researchers from populations that are disproportionately affected by substance use (including alcohol) and HIV. The proposed K24 research component will leverage valuable data sources to give mentees biomarker and biosensor research experience. These will be (1) pooling data from several alcohol studies with over 5000 participants with PEth testing, to examine correlates of PEth positivity, optimal cutoffs, and moderators; (2) leveraging data from drinkers wearing alcohol biosensors for 28 days, to further examine PEth cutoffs, and (3) examining correlates of test positivity of a of low-cost, point-of-care urine EtG test in a current study of hazardous drinkers. To be maximally effective as both a research leader and a mentor, I propose additional training to be at the forefront of the rapidly evolving alcohol biomarker/biosensor fields, and also training to be a culturally responsive mentor for persons who identify as URM. In summary, this K24-supported research and mentor training will grow the alcohol/HIV research field by proving training in alcohol biomarker/biosensor tools and applying them to alcohol/HIV issues, and by prioritizing training for scientists from URM groups that are disproportionately affected by alcohol and HIV.